Electrochemical performance of novel electrolyte solutions based on organoboron magnesium salts

A novel boron based electrolyte system based on reaction of tri(3,5-dimethylphenyl)borane (Mes3B) and PhMgCl in THF solution is proposed for the potential application in rechargeable magnesium battery. The optimized composition of Mes3B-(PhMgCl)2/THF electrolyte solution presents high ionic conductivity(ca. 2 × 10− 3 S/cm in 0.5 M solution) at room temperature, excellent Mg deposition reversibility as well as the highest anodic potential to date (3.5 V vs. Mg RE). The initial results indicate that the high-performance of the Mes3B–(PhMgCl)2 electrolyte might be attributed to non-covalent interactions arising from the excess amount of Grignard reagent PhMgCl. This study opens the door to the development of boron based electrolyte chemistry for high-energy rechargeable Mg batteries.

► We synthesized a novel boron based electrolyte system for rechargeable Mg batteries.
► We examined the electrochemical properties of this novel boron based electrolyte system.
► The electrolyte presents the highest anodic stability to date (3.5 V vs. Mg/Mg2+).
► It possesses high ionic conductivity (ca. 2 × 10− 3 S/cm) and Mg deposition reversibility.
► It paves the way to development high-energy rechargeable Mg batteries.